Comment by adrian_b

These Intel Darkmont cores are in a different performance class than the (Crestmont) E-cores used in the previous generation of Sierra Forest Xeon CPUs. For certain workloads they may have even a close to double performance per core.

Darkmont is a slightly improved variant of the Skymont cores used in Arrow Lake/Lunar Lake and it has a performance very similar to the Arm Neoverse V3 cores used in Graviton5, the latest generation of custom AWS CPUs.

However, a Clearwater Forest Xeon CPU has much more cores per socket than Graviton5 and it also supports dual-socket motherboards.

Darkmont also has a greater performance than the older big Intel cores, like all Skylake derivatives, inclusive for AVX-using programs, so it is no longer comparable with the Atom series of cores from which it has evolved.

Darkmont is not competitive in absolute performance with AMD Zen 5, but for the programs that do not use AVX-512 it has better performance per watt.

However, since AMD has started to offer AVX-512 for the masses, the number of programs that have been updated to be able to benefit from AVX-512 is increasing steadily, and among them are also applications where it was not obvious that using array operations may enhance performance.

Because of this pressure from AMD, it seems that this Clearwater Forest Xeon is the final product from Intel that does not support AVX-512. Both next 2 Intel CPUs support AVX-512, i.e. the Diamond Rapids Xeon, which might be launched before the end of the year, and the desktop and laptop CPU Nova Lake, whose launch has been delayed to next year (together with the desktop Zen 6, presumably due to the shortage of memories and production allocations at TSMC).